


Tattoo

by APHands



Category: Life with Derek
Genre: Alternate Universe - College/University, Dasey - Freeform, Emotional, Emotional Sex, F/M, Fluff and Smut, I Wrote This Instead of Sleeping, no beta we die like men
Language: English
Status: Completed
Published: 2021-03-02
Updated: 2021-03-02
Packaged: 2021-03-14 11:53:59
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 11,606
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29791512
Author URL: https://archiveofourown.org/users/APHands/pseuds/APHands
Summary: They had a very delicate dance. They would bicker circles around each other, but always knew where the line was, and never crossed it.Or, Casey gets a tattoo and needs Derek’s help.
Relationships: Casey McDonald/Derek Venturi
Comments: 9
Kudos: 61





	Tattoo

**Author's Note:**

> This is the first thing I’ve written with this length. Also the first time I’ve written smut, so please have mercy on my poor soul. Thanks to everyone in the Dasey discord for helping me realize that it’s okay to have multiple unfinished WIPs and to go at my own pace. And of course, for all the Dasey content.

_“Der-ek! Slow down, you’re going to get a ticket!”_

_“Just because you drive like a grandma doesn’t mean we all do, Spacey.”_

_“Well, I don’t want to arrive at Queen’s in a freaking casket!”_

_“Relax, Casey! I would never get you into an accident! Jesus,_ you’re _the one who taught me to drive anyway, what does that say about your faith in your own abilities?”_

* * *

  
They had a very delicate dance. They would bicker circles around each other, but always knew where the line was, and never crossed it. Of course, that didn’t mean Derek didn’t toe the line, because if there’s anything Derek was proud of (besides his Hockey God talents), it’s his ability to step right up to the line, but not cross it. Besides, it was always so much _fun_ when he found a slightly new way to tease his step sister. He said they would be the best of friends when they went to university together, and at the time, he may have been joking, but he found it was so much more entertaining to poke fun at her without the threat of the parental judgment and/or punishment.   
  


* * *

_“Derek, I’m_ not _writing your research paper for you. I said I would_ help _you with it.”_

 _“Come on, Case, I know you are just_ dying _to get your hands on this. This assignment is too perfect for you! It’s practically begging for you to write it.”_

_“No, Derek! This is for your class. I have no interest in the evolution of female empowerment in modern cinema, so forget it.”_

_“You know I can tell when you’re lying, right?”_

_“I am not lying!”_

_“Yes, you are. You have a tell.”_

_“No, I don’t.”_

_“Sure you do. The left corner of your mouth twitches.”_

* * *

But then the line became a bit harder to toe. There were times when he was _so_ tempted to take that step ( _jump, leap, dive_ ) over to cross it. And a lot of those times weren’t even significant or profound, which made him feel angry at himself for even wanting it. Like when she made him study and do his own homework, or when she had dropped off a bottle of NyQuil, crackers, and soup when he caught the flu during their first year at Queen’s. Or when she shoved his shoulder when he made a comment about her boyfriend. He found himself looking at her, in such a way that his father would disown him if George knew. Obviously Casey was like, attractive, or whatever, but Derek hated that he noticed, he hated that he wanted to act on his attraction towards her. He hated how she bit her lip when she didn’t want to admit he was making her laugh, or how she let his arm hang around her shoulders instead of pushing it away like she used to. And he absolutely _loathed_ that she was always coming to his dorm after a fight with Andrew or Aiden or _whatever his fucking name was,_ because he had to deal with her tears, he had to pick her back up, remind her that she was worth more than whatever Alex was making her feel about herself.   
  


* * *

_“God, he is_ such _an asshole!”_

_“Why are you even still dating him?”_

_“Wha-, well, he said he loves me.”_

_“That’s not a reason, Case.”_

* * *

He still absolutely refused to hug her in those moments, though. He knew that it would make her feel better, but _that_ was so much more... _intimate_ than he was comfortable with. Derek also resolutely denied himself the thought that he would like nothing more than to hold her, to kiss her, to be the one she woke up to in the morning. He did not allow himself to go there. Instead, he would _toe the line,_ between appropriate and sexual.   
  


* * *

_“Oh, my god, Derek! You are amazing!”_

_“Yup, that’s usually what the ladies tell me around this time of night.”_

_“Don’t be a pig. You know what I meant.”_

_“Oh, of course. But I do have the same effect as chocolate ice cream, so I’ve been told.”_

_“I highly doubt that.”_

_“Just shut up and eat your ice cream before I do, Keener.”_

* * *

The furthest he had allowed himself to go was Halloween night their second year. They had both gone to the same party on accident. He didn’t make it a habit to get to know her friends, and she did the same. Casey had shown up with her boyfriend (Andrew, Aiden, Alex, _whatever_ ) and he had shown up with his roommate, Troy. Troy was an idiot, but he was at least the size of the Fridge, and Derek knew if he somehow got into a fight, Troy (The Fridge II) would have his back. So he kept him around for insurance. 

It was a friend of a friend of a cousin of the goalie who threw the party. It was costume optional, thank god, because Derek didn’t really want to put in the effort of _dressing up,_ even if it was just a Halloween costume. He simply wore a plain white t-shirt and his leather jacket, with a worn out pair of jeans. Troy said he looked like a greaser, and Derek shrugged, figuring this was as much of an effort as he would put in. Plus, he could imagine some hot coed thinking he looked like John Travolta ( _gag_ ) and try to lure him away. Troy, being the idiot Derek knew him to be, was Tarzan. Yes, with only a loincloth. In October. In Kingston. Ontario. It was _freezing_ once the sun had fully set and they were on their way to the party. Like he said, _idiot._

The friend of a friend of the cousin of the goalie’s apartment was, surprisingly nice. It was definitely bigger than his dorm room, since it wasn’t actually university housing, and the party was already underway when they got there. It seemed like everyone he had ever met at Queen’s was there, all packed into the three bedroom apartment, taking up all available space and drinking like it was the end of the world. Derek had briefly scanned the room, not exactly sure what or who he was looking for, until he spotted her. 

Casey wasn’t one for big parties with lots of alcohol, Derek knew that, but there she was. Plastic cup in hand, flirtatious smile, leaning into what her stupid blonde boyfriend was saying. He glared at her, for reasons he wasn’t wanting to explore at that moment, but she was just _there._ At a party. _Drinking!_ He hated her in that moment, because _of course_ she would be there, just like she was always there when they were in high school, and at their parent’s house, and his dorm. As he glared, he paused to take in her costume, and when he realized what she was dressed as, his jaw tightened.

 _  
Babe Raider. You have_ got _to be fucking kidding._

  
Troy had already gotten them drinks, and handed a cup to Derek. “I know I’m not supposed to say this, but _damn,_ your sister is looking-"

” _Step_ sister,” Derek interrupted, “and don’t you dare finish that sentence.” He took a large gulp of his beer, wanting to avoid hearing how hot Casey was. He fucking _knew_ she was hot, he didn’t need his roommate pointing that out to him. He’d always known she was hot, it didn’t help matters any. 

He avoided her as much as he could, but finally gave in to the nagging thoughts in his head that sounded suspiciously like Casey, and after about an hour, made his way over to her when her boyfriend left to go to the bathroom, or get another drink, or wherever the fuck, Derek didn’t care. He hated AndrewAidenAlex more than he hated Truman. 

Derek expertly navigated through the gyrating bodies dancing to the loud thumping bass until he approached her leaning up against the wall of the hallway. She was looking down at her drink, and he suspected she felt out of place without her boyfriend by her side, considering she spent the whole time talking to him and no one else. She was always awkward when trying to make new friends. Casey didn’t look up immediately, until Derek spoke.

”Well, would you look at this,” he smirked, “a keener outside of her natural habitat. Are you lost?” He couldn’t help but tease her, it was what he was good at, and she always came back to him, no matter how bad the teasing was, so he suspected she didn’t hate it _that_ much. She shot her head up and smiled as she took in his appearance.

"Yeah, actually, I was looking for the T-Birds, and...wait, no, I found one!” She giggled at her own joke. He didn’t get it, but still laughed along with her.

”Could have fooled me, I thought you were on your way to kick some guy’s ass and use your _bra power!_ ” He mocked in a high pitched voice. She shoved his arm, still giggling. 

“Shut up! This was the only thing I could find! I didn’t know we were coming until after class,” she said. He could tell she was at the very least buzzed, her eyes bright and glassy. He had a slight buzz going on as well, not wanting to get too drunk too quickly. Derek leaned his shoulder against the wall in front of her, standing a little too close, but hey, it was loud in there, he had to be able to hear her. Don’t judge. 

Derek smirked, tilting his head down towards her. “I honestly can’t believe you still have that outfit. And that it still fits.” He added, his gaze drifting quickly down to her chest and back up to her face. If she noticed, she didn’t say anything. “So, where is Andrew? You came with him, right?” He questioned, trying to be as nonchalant about it as possible.

She scoffed, rolling her eyes, “His name is Adam, you dolt. He had to take a quick phone call.” She seemed a bit insecure about it, and Derek thought maybe she thought _Adam_ was not entirely faithful to her. He had certainly been forced to deal with her tears every time _Adam_ screwed up with her, and felt a fury in his chest every time he saw her cry over him. She looked away from him, back down to her drink. He didn’t mean to upset her, and wanted to immediately change the subject. 

“Hey. You, uh, wanna dance?” He offered, unsure why he even suggested it. It was a stupid move, more stupid because he hadn’t danced with her since their summer at her grandmother’s lodge, and certainly not under the influence of alcohol. 

Casey looked back up at him, her eyes as unsure as he felt. “Sure,” she said, still wary of his intentions, but seemingly relieved that he didn’t push the _Adam_ subject. He smiled and took her drink, it was almost empty anyway, and set hers and his aside on the credenza ( _thanks, Nora_ ), and took her hand. He pulled her through the mass of bodies into the middle of the living room. Derek was sure that if _Adam_ came back, he wouldn’t be able to see them thanks to the sea of drunk students surrounding them. The music was fast and deep, bass pumping wildly ( _like his stupid heart_ ) and through their bodies. He idly thought that the apartment owner’s neighbors had to either be really chill, or deaf. 

Her hand was warm, _too_ warm, in his, and he couldn’t help but notice it, to feel her fingers threaded through his own, like she belonged to him. The thought gave his gut a twist. He ignored it. Derek didn’t let go of her hand as they started dancing, only using it to pull her closer. Their bodies moved to the beat of the bass, fueled by alcohol, and _this was not a good idea._ She barely looked at him, her head down, eyes closed feeling the music in her veins. He wanted her to look at him, to _really_ look at him. They were practically anonymous in this space between others. _Please look at me._ He used his other hand to pull her waist gently closer to him, his heart pounding wildly in his chest. Her unoccupied hand moved to his shoulder, and it _burned_ through his jacket. He could feel her breath against his chest, warming him through his t-shirt. 

Her head tilted up slightly, her mouth near his ear, “What, no Crazy Legs?” She tried to joke, her voice coming out in a huff of breath. His eyes closed at the sensation of her words against his skin. He prayed she wouldn’t notice the goosebumps that raised on his neck. 

Derek let out a light laugh, “Sorry, Princess, not this time.”

She giggled, a musical sound that wrapped around him, causing his arm to slide around to her back, desperate to pull her closer. Casey let her hand on his shoulder sneak to his neck. “I thought you were the life of the party? Crazy Legs always brings in the ladies, right?” Her words sounded forced, like she was trying to convince herself of something. 

He pulled his head back and looked at her, smirk playing at his lips. She still wasn’t looking at him directly, instead her eyes seemed to be staring at his right eyebrow. “Well, I’m not trying to pull in the ladies tonight. I’m dancing with you.” 

She finally looked at him, bewilderment in her face, the corner of her mouth lifted slightly, “I never thought I’d see the day the great Derek Venturi decided to dance with his step sister instead of getting laid.” The words seemed to tumble from her mouth before she thought about what she was saying, her face frozen after she spoke. He shook his head a little, and pulled her in closer, his face lowering into the crook of her neck. 

“Shut up, Princess,” he grumbled against her skin. He felt her sigh into his shoulder, the music loud and surrounding them like a wall. He knew if they hadn’t been drinking they would not be doing this. _She_ wouldn’t be this way with him, not with her shit stain of a boyfriend lurking somewhere around, no doubt trying to find her. But it was dark, flashes of colored light around the room, full to bursting with students desperate to forget who they were for the night, pretending to be someone else. Derek could see how this had gotten way out of hand, the alcohol, the atmosphere, her _fucking costume._ Knowing that for right now, they were not Derek and Casey, step siblings; instead they were just Derek and Casey, university students getting too caught up in the night. 

His hand on her back slid up slowly, he could feel the bass in her skin. Derek couldn’t help but be pulled in by her presence. He couldn’t help they way his hips swayed with hers. He also couldn’t help ( _no, really)_ that they were being unwittingly pushed closer together by the other dancing bodies. Someone had fallen against his back, causing his body to press flush against hers, his face still her neck. His arm tightened against her back, pulling her in closer. Her hand gripped his hair, and he could feel his skin prickle at the sensation. He took in a deep breath, trying to force the thoughts out of his head, that they were basically _this close_ to mimicking sex, her hips against his, gyrating with the music. He knew she didn’t dance like this. She was practically a professional, trained in ballet and jazz, she didn’t dance like she was trying to... _get off._ The idea that she was indeed dancing like this, _with him_ , sent a thrill down his spine that he didn’t want. He didn’t want to want her, he wasn’t allowed to want her. His mind argued with his body, _they weren’t themselves,_ and he struggled with his morality ( _who knew he had a conscience_ ) and whether he should put a stop to this before it _really_ got out of control. 

The thought left him when Casey tightened her grip in his hair and she pressed herself into him. He could feel her breasts on his chest, feel each breath she took. Derek groaned into her neck, letting go of her hand that seemed to tether him to reality, and curved it over her hip, and _pulled._ He felt himself harden, her pelvis writhing against his. Derek trailed his lips up the side of her neck to her ear. _Not kissing. Do not kiss her neck._

He felt her gasp, heard her slight moan over the booming bass and the shouts of _shots shots shots_ from somewhere in the apartment. He didn’t care. There was only _him and her._ His breath shuddered against her ear, “ _Case,”_ he whispered, but he knew she could hear him. 

Perhaps it was a good thing, Derek couldn’t decide, that he spoke, because that seemed to break the spell she was under. She jerked her head back, questions in her eyes. Her face flushed, pink and _absolutely not adorable,_ and he struggled to find his voice. 

“We’re drunk,” he finally blurted. 

She let go of his hair, moved her body back away from his. He let her go. 

“Y-yeah. I’m wasted,” she said lamely. He knew she was lying. Casey has never been able to tell a convincing lie to him. Maybe to other people, but _not him._ He couldn’t look away from her, blue eyes searching his for answers he couldn’t give her. 

“Me too.”

She looked like she was going to say something else, her mouth opened as she drew in a breath, but of _fucking course-_

“Casey, honey?” _Fucking Adam._

She broke her gaze, turning to face Adam. “Hey, babe, where have you been?” She asked innocently. She looked back at Derek before he could answer, “‘I’ll see you later, Derek. Enjoy the party.”

And she left. 

She left, and he let her go. Casey wasn’t supposed to dance with him. She wasn’t supposed to be the object of his desires. She was his step sister, and he her step brother. Not Derek and Casey, university students. Derek and Casey, step siblings.

* * *

_“How come you never applied to UBC?”_

_“Why would I do that?”_

_“Well, you almost dropped out for her, I thought you’d want to try being with her again.”_

_“…”_

_“Derek?”_

_“Why didn’t you go to New York with him?”_

* * *

It wasn’t exactly difficult to not seek her out. They lived in different buildings, her dorm on the other side of campus, they didn’t share any classes, and they had completely different after class schedules. He wouldn’t seek her out. And at first, she didn’t go to him either. He thought maybe after, since he _did_ end up drinking enough that night to vomit in the potted plant on the balcony of that one guy’s apartment, maybe she drank enough to forget it. She was a lightweight, after all. But that wouldn’t be the Casey way, she was responsible, he wasn’t. She wouldn’t dare get black out drunk at a party where she’d known no one but her boyfriend and himself. It wasn’t safe. But he had almost hoped that she did, so he wouldn’t have to face her after. Or so he could just explain her absence from his life away as some kind of fluke, that she just didn’t remember that he was there, or that her boyfriend had left her in the middle of a party for close to half an hour for a _fucking phone call._ If she wasn’t fighting with _Adam_ about that then she wouldn’t have too many reasons to come to his dorm. 

But she did come, eventually. It was a couple of weeks later, but she did show up. With tears.   
  


* * *

_“I have never skipped before, I’m not going to start now!”_

_“Casey, you are burning up. You have a fever.”_

_“I’m fine! It’s just stress!”_

_“No, it’s not. You’re sick, you’re staying here. I‘ll find someone from your classes to get you notes. I’ll be back in a little bit. I think I still have the NyQuil you gave me.”_

* * *

He heard a frantic knocking at his door, idly wondering if Troy had forgotten his key. He got up from the couch and moved to the door, glancing at the key hooks and noticing that Troy’s keys weren’t there. 

“Casey?” 

He took in her appearance; she was crying, _again,_ and dressed for what he assumed was bed, considering her pajama pants and long sleeved shirt. “Where’s your jacket?! It’s freezing out!” He asked, incredulous as to why she had come over in the cold November without warmth. He noticed she was shivering, and pulled her in. “Come on, let me get you a blanket.” He shut the door, guiding her to his couch to sit. Derek moved quickly to his room and grabbed the comforter off his bed to wrap around her. He sat next to her on the couch and rubbed his hands up and down her arms in an attempt to warm her more efficiently. “What happened?” 

Casey, still trembling, looked at him with wide, watery eyes. “Adam, he-" she swallowed, “I caught him.” 

Derek stilled. He felt the familiar fury in his chest whenever she came to him, crying about _Adam._ He didn’t want her to say anything else, he didn’t think he could handle it. When Truman kissed Vicky that one time in Toronto, he felt a similar rage, but not wanting to make a huge scene for Casey’s sake, didn’t do what his gut was telling him to and _beat the shit out of him._ Now, because his relationship with Casey had morphed into something more undefinable but definitely not _familial (he wanted to throw up at that term),_ he took it harder when she was mistreated by stupid boyfriends who didn’t know a good ( _wonderful, beautiful, amazing)_ thing when they had it. 

_"_ You don’t have to say anything else if you don’t want to,” he told her, with absolute sincerity. He really didn’t want to hear how _Adam_ had cheated on her. Derek knew exactly what she had meant when she said she caught him. He made a mental note to mention this to Troy. "What’s his last name?” He asked.

Casey shook her head. "Don’t. I know what you’re trying to do, and I’m telling you, _don’t.”_ She was determined. 

Derek sighed. "I just want to know. I’m not going to do anything.” It was true, _he_ wasn’t going to physically do anything. Troy would. 

She gave him a hard stare, “And neither is Troy. I just want to forget about him.” Her tears were still coming, but at least she wasn’t sobbing. Derek considered how she had grown up a bit since high school. Yeah, she was still crying over a guy, but she wasn’t like end-of-her-existence bawling. He slowed his hands on her arms, changing his vigorous rubbing to warm her into a comforting gesture. Despite his no-hugging rule for himself, he fought the urge to wrap his arms around her. He knew what she felt like in his embrace, thanks to Halloween, but resolutely denied himself that pleasure. _Too intimate._ Derek couldn’t help but scoff at himself in his head. _Hugging is too intimate, but grinding at a party with a hard on isn’t._

"Do you want some ice cream?” He tried with a lopsided smirk, lifting his shoulders in what he hoped was a comical way. Anything to help her to stop crying and crack a smile. She sniffled, shaking her head. 

"Do you have any tissues?” She asked after taking a deep breath. 

"Yeah, I’ll be right back.” He got up to head to his shared bathroom, under the sink was a box of tissues he kept for just such occasions as this. The very idea that he kept things in his dorm that were just for her use caused a pain in his abdomen. He tried not to think about it too much. She was working her way into his life in ways he never imagined. When he walked back into the living area, he noticed she sat very still on the couch, wrapped in his blanket, her face in her hands. She was still sniffling, but he held out hope that she was going to be fine, because again, she wasn’t sobbing. Derek took this as a good sign.   
  
He sat back down next to her, his right knee touching her left. She didn’t move away, so neither did he. "Here. Are you hungry? Did you eat dinner?” He felt a little stupid asking, she was dressed for sleep after all, and it was nearing ten. 

“I’m fine, I ate.” She said, he voice muffled a bit by the tissue as she blew her nose. Casey roamed her eyes hesitantly to him, she looked like she had more to say. 

"What’s up, Spacey?” He asked, knowing that if she had more to talk about, she would need prompting from him. She knew he didn’t do tears, or feelings. 

"Well, I kind of, um, _left_ Adam at my dorm.” She murmured. 

Derek stared, waiting for her to go on. "Okay...?”

She huffed. “Can I, I mean. Would it be okay if I stayed here tonight? I can take the couch!” She rushed out, “I just don’t know if he’s still there, and I don’t want to risk running into him tonight.”

Derek paused. Casey had never stayed the night at his dorm, and he never stayed at hers. Granted, he wasn’t actually allowed to even if he wanted to, she lived in an all-female residence hall, and he in a mixed-gender environment. Before he could really think about it too much, he blurted, “Yeah, sure. Fine, it’s fine.” _God_ he sounded like an idiot. But, Casey finally gave him that smile he wanted to see. 

"Thank you,” it came out as a whisper, and he wished he could bring her to his bed and hold her until all her tears dried up and she never had a reason to cry over a guy again. 

"I just need to let Troy know you’re staying the night, so he doesn’t have a heart attack when he gets back tonight.” He said, pulling out his phone to text Troy. 

“Do you have an extra blanket? I don’t want to steal yours,” she said with a giggle. _Beautiful._

Derek glanced up at her from his phone, “No, it’s alright, I can just sleep with the sheet. I usually don’t use the blanket anyway, too hot.” He smirked at her, wanting to continue their playful banter now that she had smiled and giggled. It was going to be a long night. 

* * *

_  
“I can’t believe I don’t have my camera! I need to document this day in history!”_

_“Shut up, Keener. It’s not that momentous_. _”_

_“Ooh! Look at you, Mr. A+ using new vocabulary!”_

_“Stop making this into a thing, and don’t expect to see another one anytime soon.”_

_“You know, I’m really proud of you, Derek.”_

_“Thanks, Case.”_

* * *

  
He stayed in his room that night, and she stayed on the couch. Casey never came to his room, even though he secretly wished she would, and she wasn’t there when he woke up the next morning. He tried not to be disappointed. 

* * *

  
Casey would stop by more often, to help him study, to watch a movie since her room didn’t have a television, or just to hang out with him. Derek certainly wasn’t going to complain about her continued presence in his dorm anymore, he got along with her better than he ever had. He still pranked her, still teased her, but not maliciously any longer. He found he was enjoying their newfound not-quite-friendship. She always gave as good as she got from him, too. Casey challenged him in ways no one else had ever dared to, not even Sally. Derek, even with his denial of his feelings for Casey, acknowledged how fucked up it was of him to compare her to Sally. Like most of his thoughts concerning Casey, he tried to ignore it. 

He was doing it pretty well, he thought, at keeping his foot firmly behind the line, sometimes testing himself and letting his toe close in on the line, and sometimes he withdrew. It was a dance of limits on himself. He couldn’t help it if Casey left the sexual innuendo door wide open for him to walk through, he always would just to see that embarrassed blush bloom her cheeks, and she would bite her lip in that way he ~~loved~~ hated. Derek thought they had a good thing going, a teasing back-and-forth between them, he didn’t want to lose that.   
  


* * *

_“Der-ek!”_

_“Lighten up, Princess. It was just a joke.”_

_“You can’t just…_ say _stuff like that to me!”_

_“Sounds like I just did.”_

_“No, you can’t. It’s not appropriate.”_

_“Casey, when have we ever been appropriate with each other? You wish death upon me whenever you get mad, that’s hardly within the confines of the normal sibling relationship.”_

_“_ Step _sibling relationship.”_

 _“What’s the_ difference _, Case?”_

* * *

They went home for Christmas. The car ride wasn’t uncomfortable, Casey drove (she insisted) and Derek napped peacefully in the passenger seat. When they arrived at their family home, he couldn’t help but feel the sharp sting of _guilt_ he always felt whenever they went back home. Usually it only lasted a day or two, and they would fall back into their old behaviors towards each other. They bickered over little things, but it felt forced. Almost as if they were both trying to maintain the illusion of animosity between themselves to fool their family. They exchanged gifts on Christmas morning, he got her a t-shirt that said _Future Crazy Cat Lady,_ and she got him a children’s book on table manners. They never were sincere in their gifts towards each other, always teasing or gag gifts. The family had gotten used to it after so many years, and paid no attention, although George asked if he could borrow Derek’s book, for Simon’s benefit, not his.   
  


* * *

_“I don’t know how we managed to live in the same house. You’re insufferable.”_

_“Ah, come on, Spacey, you missed this just as much as I did, don’t deny it.”_

_“Yeah, as much as I’d miss a hole in my head.”_

_“You know, now that you mention it, I could go without your mouth flapping away every second.”_

_“…what? That doesn’t make any sense.”_

_“Your mouth, it’s a hole in your head.”_

_“You’re an idiot.”_

_“Aw, you’re so cute when you sweet talk me.”_

* * *

After spending last New Year’s at the McDonald-Venturi house, this year they decided to go back to Kingston to ring in the new year with their friends. Not together, because they had no mutual friends. Derek was going to a party thrown by an upperclassmen on the hockey team, and Casey had a friend in a sorority who was throwing a party. He wished they could be together at midnight, and once again ignored the twist in his gut when he watched the countdown and the ball drop on the television. Derek wasn’t alone though, he had found a cute redhead to share a midnight kiss with. He hoped Casey wasn’t alone, that she could be surrounded by her friends and not be reminded that she didn’t have a boyfriend to kiss at midnight. She did have a history of wallowing, after all. 

Around two in the morning, as he was getting his hand under the redhead’s shirt, his phone rang out. No one called him this late, so he knew it could only be one person. 

The redhead groaned and tried to take the phone away from him. "Come on, seriously? You’re going to answer some other chick while you’re with me?” She bit out, angrily.

Derek gave her a look and left her on the couch of the party host’s house. He walked out onto the patio to better hear as he answered. 

“Case? You okay?” 

"Der! What’s up?” 

He blinked. "...are you drunk?”

”What! No, I am just very-" someone took the phone from Casey. 

"Hello?" A feminine voice called into the phone. 

Derek scrunched his nose, “Who is this?” He asked. “Where’s Casey?”

“This is her friend, Samantha. She came to a party with us.” The voice, Samantha, said. 

“Well, is she okay?”

”Technically, yes-“

”What does that mean?!” Derek interrupted. 

“Relax, Jesus. She’s incredibly drunk. I mean we all kind of are, but anyway. We’re at True North Tattoo-"

“What?! Don’t tell me-"

“Stop interrupting me, my _god._ ” She giggled in the phone, Derek rubs a hand over his face in a very frustrated gesture. If drunk Casey got something she would regret, he’d never hear the end of it. “Anyway, yes, we all got tattoos, it was kind of like, a group dare? But she doesn’t want to get a cab, she wants you to come pick her up. She’s _very_ drunk.”

He groans. _Of course. Of fucking course._  
  
“I’ll be there in twenty. _Don’t_ let her out of your sight.” Derek ordered. He couldn’t believe Casey. She’s never done anything as reckless as this. 

He leaves the redhead, she had passed out on the couch. Without a second glance at her, he grabs his keys and leather jacket and heads out the door to get his incredibly stupid step sister.   
  


* * *

_“Which do you love more, hockey or directing?”_

_“I really don’t know. They are two very different passions of mine, it’s hard to compare.”_

_“Well, if you had to choose one over the other for, like, rest-of-your-life career stuff, which would you choose?”_

_“What about you? Law, medicine, or dance?”_

_“…I don’t know.”_

_“See? If you can’t choose, don’t expect me to be able to either. How you feel about dance is how I feel about hockey. And how you feel about law or medicine is how I feel about directing. All very different passions, but I still love them the same.”_

* * *

"Derek! Oh, my _god!_ Guess, guess what I did!” She squeals when he shows up. She’s without her jacket, wearing only a tank top that is absolutely not appropriate for the mid-winter night. She’s standing outside the shop with three other girls, one of them he assumes is Samantha, and they are holding each other up in their shared drunken cackles. He doesn’t know if he should laugh or be angry with her for making such a rash decision about something so permanent, but she’s _happy._ Even if she is drunk, she’s laughing and smiling and looking at him with those _eyes—_

“I’m going to go off on a limb here, but I _think,”_ he stands before her, arms crossed, “you got a tattoo?” His head is tilted down towards her, eyebrows quirked up in that way that means he knows he’s right.

She chuckles softly under her breath, and moves forward to shove at his shoulder, “Who told?” She says in the same way that Marti does, and that makes him uncomfortable.

Instead of dwelling on that feeling, he focuses on the drunk woman in front of him. "Well, Princess, you’re drunk, on New Year’s, in the middle of the night, in front of the closest tattoo shop to Queen’s. It’s not hard to figure out.” He looks directly into her eyes, they are glassy and wide, a bit red around the edges, and he suspects she might have cried a little at the pain. “So, what did you get?” He can’t help his curiosity. She doesn’t have anything on her arms, or her hands, or her neck, or her collarbone, and then he realizes that he’s _checking her out,_ and immediately looks back to her face, the tips of his ears turning red.

Then she bit her lip, not in the way he was used to, though. Her mouth was smiling, bottom lip stuck under her perfectly dazzling teeth. He sucked in a breath, suddenly nervous as he awaited her response. 

“I’ll, uh, show you later,” her eyes twinkled at him, "take me back to my dorm, please.” The girls around her snickered conspiratorially, heads together like they knew a secret. It reminded Derek of grade school, when the girl was encouraged to talk to her crush by her friends. He had certainly been on the receiving end of those confessions many times, and it never failed to boost his confidence. Now, though, it almost scared him. What did Casey tell them about their relationship? They know he’s her step brother, right?

_Right??_

“Yeeah, _Derek,_ take Casey to her _dorm!_ ” One of them, a short blonde teased at him. He narrowed his eyes at the group of them. Something was amiss. He didn’t get it, and he _hated_ not being on the inside of a joke, because that’s what this was, right? It had to be a joke. It _had_ to. 

Casey rolled her eyes at her friends, and moved forward to grab Derek’s arm. She stumbled on her own feet, prompting him to mutter " _Klutzilla,”_ before taking his jacket off and placing it over her shoulders. She bundled up in it, closed her eyes and smiled, like she was content. Her hair was unbound, tucked under the collar of his leather jacket, and it pained him to see her in it. 

Derek sighed and dropped his arm over her shoulders to help her walk to the car. "Night, ladies,” he called out to the group, their cab having just pulled up to the curb. He walked the two of them around the back of the building to the dirt parking lot, and helped her into the passenger side. It was then that he noticed a plastic bag hanging from her wrist, that she placed on the floor of the car. He knew it for what it was, after care instructions and likely a healing ointment to ensure the tattoo didn’t scab over or get infected. He had his own kit when he got his tattoo on the inside of his right bicep. During their drive back to her dorm, she babbled on about her night; the party she went to, the truth or dare that every girly movie always included at a girls sleepover party, and how each of the four girls had gotten a tattoo that signified their passions in life. Derek wondered what she could possibly get, a fucking textbook? A research paper with an A++ in red at the top? When he pulled into the parking lot outside her dorm, she let out a gasp. 

“What?” He asked. 

“I think—" she searched her pockets, the floor, and the backseat. 

“Spacey, you don’t have anything in the back, and where’s your jacket, by the way? Is this a new habit of yours?” He asked impatiently.

She looked over to him, eyes wide with worry. “I think I left my jacket and keys at the tattoo shop,” she whispered. Casey bit her thumb, a nervous habit he noticed. Derek let out a frustrated groan. 

“Fine, we’ll go back in the morning. You’re staying with me tonight.”   
  


* * *

_“What are you looking at?”_

_“Sorry, I didn’t— I mean. I’ve just never seen it before.”_

_“Seen_ what, _exactly?”_

_“Your scar. From the appendectomy.”_

_“Oh. Well, I don’t like it being displayed.”_

_“Then why are you wearing a two piece?”_

_“Just—stop staring. You’re making me uncomfortable.”_

_“Are you_ blushing?!”

_“No!”_

_“Yeah, you are. You can’t hide a blush in a two piece! And look, it goes all the way down—”_

_“Der-ek!”_

_“Cas-ey! It’s alright, I have that effect on women, don’t worry.”_

* * *

Derek didn’t want to think about the fact that this was now the second time she was staying the night at his dorm. She tripped on the stairs on the way up, and he grabbed her by the arm to hold her up. 

“Are you still drunk, or is this just normal Klutzilla?” He couldn’t help but snicker. 

“I’m sobering up, I think,” she had a serious case of the giggles, which led him to believe that yeah, she’s still drunk. Or at the very least, tipsy.

When they got into his dorm, he led her to the couch, instead of his bedroom. Troy was still out partying, seriously, that guy could party for days and not get tired. But Derek didn’t want to bring her to his room, the line could get blurred, and he was _not_ going to do anything with a very obviously not-sober Casey. 

And then, _and then,_ she had to open her big, stupid, ~~sexy,~~ mouth, “Can we, um, go in your room?” She sounded as nervous as he felt, and that terrified him. 

Derek swallowed, ( _he did NOT gulp, he’s too manly for that)_ and stuttered ( _dammit_ ) “S-sure.” 

Casey smiled a nervous grin, which he distinctly recalled as the same one from _same difference,_ and his heart skipped a beat. He briefly thought he should go see a cardiologist, because that can’t be normal. His palms start sweating as she leads the way to his room with her plastic bag in hand. She took off his jacket and placed it neatly on his desk chair. 

He was incredibly nervous. Which was ridiculous, because he’s a manly man, he’s suave, he could get any girl he wants, because he _always_ gets what he wants—

Except he doesn’t, not _really._

Derek was _not_ supposed to want her. Casey is not someone he can get, he can’t _be with her._ Not in that way. They are Derek and Casey, step siblings. Not Derek and Casey, university students. He stood there, in the middle of his bedroom ( _and mid-internal crisis_ ) fumbling with his hands. What was he supposed to do? It’s not like she had never been in his bedroom before. She had certainly barged into his room at her leisure at home, and he to her room as well. This wasn’t the first time they had been alone together. There was no reason to be nervous. No reason for his hands to shake in the pockets of his jeans. 

Casey sat on his bed with her plastic bag in her lap. "So, the guy told me that I need to put this ointment on it, you know, to keep it from getting ruined, and, well, I can’t reach—"

She twisted her hands together. He wondered where this tattoo was, that she couldn’t reach it herself. There weren’t many places he thought she couldn’t get her hands to on her body, considering her incredible flexibility, and—

_Do not think about her hands on her body._

He cleared his throat, trying to find his voice. “What, um, what did you get?” He reached up to rub the back of his neck. He wanted to ask _where_ but he had to censor himself. 

She took a deep breath, looking like she was trying to build courage within herself. Derek had seen her do that many times, before a big exam, before Dance Mania, before approaching Trevor for their stupid bet, and before that dumbass pirate play he had unfortunately been involved with. Casey stood from his bed and turned her back towards him.

Derek held his breath. He could see the hints of ink in her skin peaking out of the top of her tank. She reached around herself and slowly pulled the hem of her shirt up.

He definitely needed to make an appointment to see a cardiologist, because he didn’t think his heart had ever beat this fast before. He was certain he was going into cardiac arrest. 

He could tell she was wearing a bra, the straps of which were visible next to the spaghetti straps of her tank, but when she lifted her shirt, he saw the bands were unfastened and hanging uselessly at her sides. His throat went dry at the sight. Casey lifted her shirt fully up to her shoulder blades, the front of her shirt was still covering her chest. Then he saw her tattoo, and it was _beautiful._

She told him it was to signify her passion in life, and it did. He felt stupid for not thinking of it before. It was a female dancer, back arched, naked, toes pointed. It wasn’t a realistic representation of the female body, nor was it cartoonish; it was sweeping elegant lines, details forgone for the illusion of grace, arms out and incomplete. But he thought that only added to it’s beauty. It was so _Casey_. It was simple, not too large, sitting squarely in the middle of her back, maybe the size of his palm. His hands itched, _ached,_ to touch it, to touch her. The air in his lungs left him in a rush. 

“It’s beautiful,” he didn’t mean to whisper, but felt it was appropriate for the piece of art in front of him, like he was at a gallery and not wanting to disturb the atmosphere.

Casey cleared her throat, “Thanks. So, like I said, I can’t fully reach it. And I need to put the ointment on it.” She let go of her shirt to rifle through the bag on his bed, pulling out a tub of Aquaphor healing ointment. He was familiar with it, he had a tube in the bathroom cabinet leftover from his tattoo experience. She didn’t turn around to face him, instead reaching her arm back to hand it to him, a silent invitation. 

He hesitated. If he did this for her, he wasn’t sure he could go back to not knowing what her bare back felt like against his finger tips. He didn’t want to go back to being Derek and Casey, step siblings. He would be taking a deliberate step over the line, not sure if he could ever uncross it. After a few skipped heart beats, he moved forward, and took the tub from her hand. She wouldn’t need this whole thing for a tattoo of that size, but he figured that was just Casey being Casey, wanting to be prepared for anything. His thoughts were tripping over themselves, a war of his mind and body, wanting to immediately go to her and take her in his arms and never let go, instead forcing himself to be slow. He didn’t know what this meant for her, and he didn’t want to misread her. Especially because she had been drinking. He decided that yes, he was going to help her, but that’s _it._ Nothing else was going to happen tonight, he didn’t think his heart could handle any more new territories that might open from this act.

Derek heard her let out a shuddered sigh. He felt the same stuttered breath in his own lungs. He stepped closer to her, she was _right there,_ their proximity very blatant to him. He opened the tub and tossed the lid on his bed. 

“I’ve done this before,” he assured her. He knew she was probably blanching at his disregard of the after care instruction sheet in the bag. 

“I know,” she whispered. Casey moved her hair over her right shoulder out of his way, assuring no strays would stick to the ointment. He dipped his forefinger and middle finger into the tub, gathering a liberal amount to prepare to rub into her skin. Derek could feel his pulse race, and willed his body to remain calm. It wouldn’t be appropriate to get an erection with Casey exposed in front of him...

 _Like it wasn’t appropriate on Halloween._ The memory of that night teased at the back of his mind. 

“Can you—" he tried again, his voice coming out like a croak, “can you hold your shirt up? It’s slipping down.” He couldn’t believe that was a sentence that came out of his mouth, to _Casey,_ of all people. 

“Oh! Sorry,” she nodded, and her hands went over her shoulders to grip her tank, elbows pointed towards the ceiling. 

“Thanks.” Why was he still whispering? Nobody else was here! It was just him and Casey! Alone!

 _Alone with her shirt up and her bra undone._

He took a deep breath to steady himself. He could _not_ believe this was happening. This had to be a dream. He had to have passed out drunk at the party and his twisted mind came up with this. Derek bit the inside of his cheek, hard. _Nope, not a dream._

With a final intake of air, he pressed his fingers to her back. She was _warm._ He knew she was likely still sensitive, so he tried to be gentle. His two fingertips glided over the ink delicately, like he was afraid she would break if he pressed too hard. He could hear her breathing, ( _or was that his own?_ ) stilted and shuddering. Goosebumps erupted over her back, her grip on her shirt tightened. The possibility that Casey might be as affected as he was gave him a pleasurable thrill low in his abdomen, migrating down to his groin. He dipped his fingers back in the tub to gather more, and returned to his ministrations. He could see and feel each breath she took, inhaling deep and expanding her lungs and by consequence, her back. It pushed against his fingers with every intake of air. He tossed the still open tub of ointment onto the bed, not caring if it messed up his comforter, he didn’t need anymore of it anyway; he was almost done covering her ink with it. His now free hand moved to her left hip, exposed skin begging for him to touch. He kept rubbing the ointment into her skin, but without the intention of following the after care instructions, he just wanted to keep touching her. 

Casey sighed, and let her hands loosen on her shirt, eventually dropping her arms to her sides. But she didn’t moved away, instead leaned into him. His breath quickened at her action, stepping closer to her. His fingers drifted away from her tattoo, trailing down her spine, to the right, and finally to the curve of her waist. He let his fingers roam up and down her side, and she didn’t stop him. Derek brought his head to the exposed crook of her neck, his lips just barely touching her skin. He could see her pulse, rapidly beating in her neck. His left hand stayed put on her hip, his thumb rubbing circles against her skin. 

This was the moment he knew he could never come back from. He warned himself this would happen, that he could never forget this. It was this exact moment, that he knew. 

_He knew._

She would forever be forefront in his mind, he knew he could never, ever, look at her as his step sister, could never call himself her step brother. He closed his eyes tightly, hoping against hope that she wouldn’t hate him for this. 

_"Casey...”_ he didn’t mean to sound out of breath, but that’s what she did to him. He couldn’t breathe, she sucked the air out of his lungs whenever she was near him, she made his heart race, made his blood pump, exhilarated him. 

She took his left hand in hers, and he was scared for a moment, that she would push him away, yank her body back from him and shout at him. 

But she didn’t. 

Casey guided his hand around to her stomach, pressing into her. “Derek...” her voice was quiet, but he heard her. He nudged his nose against the side of her head, taking in the smell of her vanilla shampoo. His heart thumped wildly in his chest. "Derek, I’m not drunk. I mean, I _was,_ but it turns out getting stabbed thousands of times with a needle will sober you up pretty quick.” Casey’s voice was more clear, she didn’t stutter or slur. He held the air in his lungs. She continued, “And...I wasn’t drunk on Halloween.” 

He let out a groan, pulled her flush to his chest. His mouth found her shoulder, kissing lightly. _This is happening._ She tilted her head back against him, giving him more access. Her shirt, still bunched up under her breasts, cut low, allowed him a peak to her cleavage. 

“Neither was I,” he admitted with a sigh. He gripped her waist tighter, never wanting to let her go. Her hand left his to reach around his neck and grip his hair. It sent tingles down his spine. He kissed his way from her shoulder to her jaw, nibbling lightly at her skin. She let out a broken moan, her eyes closed, and turned her face to his. She was so close, his lips brushing hers, and opened her eyes. His half-lidded gaze bore into her own. Her eyes had always captivated him, the bright blue commanding his attention any time she looked his way. They always had, ever since he met her all those years ago. Whenever they had an argument, and she would stare him down, he always found himself trapped by her eyes, the fire he saw in them fueled his attraction for her in ways he never felt with any of the girls he had been with or dated.

“Derek,” he felt her words against his lips, “please, Derek. _Kiss me,”_ He brought his left hand to her cheek, held her head steady, and covered her lips with his own.

Derek felt the tension leave his body, as he held her against him. The kiss started slow, gentle, afraid to move too fast, but when Casey responded eagerly, he let himself go. He slanted his lips against her, his mouth opened slightly to allow her tongue to meet his. The feeling of it made his hands go numb, and he felt lightheaded. He figured the rushing blood in his veins was partially to blame, as it definitely wasn’t going to his head, instead down, to the most sexual part of him.

Casey turned in his arms to face him fully, and wrapped her arms around his neck, desperate to pull him closer. He in turn reached his hand to the back of her head, guiding her movements, and let his arm curl around her back to press her against his hard body. She lifted herself to her toes, raised her left leg to his hip. Derek’s hand followed her movement to grip her thigh tight.

Casey moaned against his lips, and he cherished the sound and the feel of it. She moved her hands down his chest, to the hem of his shirt, and lifted it. He pulled his mouth away to allow her to take it off. Her eyes roamed his bare chest. This wasn’t the first time she had seen him shirtless, he knew, but it made him flush in a way he hadn’t any of the previous times. He moved to remove her shirt, it was practically useless anyway, bunched up above her waist, but he hesitated, remembering that he bra was already unfastened and likely wouldn’t cover her breasts fully. Derek looked into her eyes for reassurance. She gave him a quirk of her lips, and stepped back. He was concerned she had changed her mind for a split second, then she turned around to place the tub and lid into the plastic bag, and dropped the bag on the floor. With her back still towards him, she lifted her shirt off fully. His jaw dropped. The bands of her bra still hung uselessly at her sides, then she took it off.

Her completely bare back before him, he advanced on her quickly. Derek’s hands immediately reached around to cup her breasts as he sucked on the pulse in her neck. Casey moaned, louder this time, and he couldn’t help but let out a strangled moan himself, against her neck. Their breathing quickened, fast paced and out of control. She turned in his arms, and he finally felt her bare torso against his. Derek kept his mouth fixated on her throat, alternating kissing, biting, and sucking, as Casey snaked one arm around his waist to his back, her nails digging into his skin. She brought her other hand to the back of his neck and gripped his hair, gasping in breaths.

He moved her towards his bed, laying her down against his pillows and lowering himself on top of her. She opened her legs to let him settle in the place he most wanted to explore. Derek felt like he was in the middle of the _best_ dream of his life, but he knew this was reality. Casey was there, with him, and _she wanted this, too._ At the very least, she wanted him on a sexual level, but he knew, the possibility was there, that she could maybe _love him the way he_ —

“ _Fuck,”_ he whispered harshly into her neck. His hands roamed her upper body, wanting to touch every inch of her skin. Casey’s hips arched up against his, and there was no way, _no way,_ she couldn’t feel the effect she had on him. If what they did in the living room of the Halloween party was anything close to mimicking sex, then what they were doing _now,_ well, this felt like the first chapter of a long novel detailing all the ways he would take her, give her every ounce of pleasure that she gave him. “Case, you have _no idea,”_ he kissed her cheek sloppily, “how long,” he kissed his way to her mouth, “I’ve wanted,” her tongue twirled with his, “I’ve _needed,”_ he thrust himself against her center, “ _I need you,_ so bad.”

Casey moved her pelvis with his, thrusting up against him in ways he never could have imagined she would. Her desperate gasps and moans gave him life, surged through his veins. The way her body moved and writhed with his was so _fucking perfect_ , he was almost afraid he wouldn’t last through to the final act.

She panted against his ear as he trailed his lips over her neck, “I _know,_ Derek, I felt it, too.”

He brought his face back to hers, his dark eyes searching hers, admiring with wonder. _She felt it too._

Derek put his weight into his left hand, setting it next to her head, while his right threaded through her hair. His chest tightened at the sight of her, breathing heavily under him, bare from the waist up, lips swollen and red from the force of their mutual want. She had a pink tint to her cheeks, and it was just— _so adorable,_ he felt a flood of emotion he didn’t know he possessed wash over him with such enormity. He was afraid he would blurt out everything he was thinking and feeling too soon, before he could fully process and absorb what exactly they meant.

Casey felt for his hand in her hair, intertwining her fingers with his. She looked into his eyes so deeply he thought for sure she could read the thoughts in his head like an open book.

“ _I know,”_ she spoke softly, not quite a whisper, and he felt her words reach down into his chest and _squeeze._ He let the weight of what she said bring him back down to her, and he kissed her deeply, wanting to transform his emotion into physical action, hoping she could understand and translate it into what he meant.

Derek left his hand in hers, pressed firmly into the mattress, while his other trailed down her body to the button of her jeans. He paused for a moment, waiting for her to stop him, and when she instead let out a moan against his mouth, he unfastened the button and drew down the zipper. She pulled away from him to look down at their bodies, where his hand rested at the hem of her lavender panties. Casey sat up a bit to start pushing down her jeans for him, and he tilted his body to the side to help her. Derek tossed her pants to the floor, while she went for his jeans next. He laid back against the bed and Casey took that opportunity to straddle him while she removed his bottoms. The outline of his erection in his boxers twitched when she touched it, and he gasped at the sensation. Derek found himself repeating _this is real_ like a mantra in his head, the reality that they were in that position, that she was on top of him in just her underwear was enough to fuel his fantasies for years to come.

His hands moved to her hips, pulling her to sit firmly over his groin. She rested her palms on his firm chest as she ground herself on his cock. He could feel more of her through their underwear, the heat and wetness emanating from between her legs empowering him to thrust up against her wildly, and she eagerly responded in kind.

Casey fell forward, resting her forehead against his collarbone, panting heavily. “Derek, please…”

His hands explored, drifting from her hips to grip her rear. He pressed his face against her head, “Please, what, Princess?” He grinned. He still had to tease her, despite the ache to be inside her.

Casey huffed, false indignation in her tone, “Der-ek!”

Music to his ears.

He laughed, his left hand roved up her back to fist in her hair, holding her in place. She nipped playfully at the skin stretched over his collarbone, causing him to hiss in pleasure. His face morphed into a more serious expression, though she couldn’t see it.

“Say it,” he almost pleaded to her. She whimpered against him, clearly embarrassed, he could feel the heat of her blush on his chest. “Casey, I need you to say it.”

She lifted her head to look into his dark eyes. Derek drew his brows together, trying to get her to understand what he was really saying with his expression. He couldn’t do this if she didn’t confirm what she wanted from him. He couldn’t live with himself if he just assumed and _took_ from her, without knowing if she was ready to give all of it to him. Even before her, with his exes and one night stands, he always waited for the explicit consent to continue.

Casey brought her lips a hair’s breadth away from his, “I want this. I want you, _please,_ Derek. I need you inside me.”

That did it for him.

Wasting no time, he closed the distance between their mouths, slanting his lips against hers in an open kiss. He let his hand move from her rear to her hip, sliding her panties down as much as he could. She lifted herself off of him to remove them the rest of the way. Derek’s eyes widened, not daring to blink, lest the image of her completely nude form disappear with an irrational fear slipping into his thoughts.

Casey smiled down at him, her hands coming to rest at the hem of his boxers. Derek was almost certain his heart was beating visibly in his chest, not able to hide his affection for her. She moved to hover over his legs, taking his underwear with her, exposing him completely to her gaze.

“Come here,” he whispered to her, lovingly. He didn’t mean to, but it seemed that she was able to get him to expose his feelings more and more this night. She crawled back up to him, holding herself over his erection, just barely grazing the tip of him. Her forearms rested on either side of his head, caging him in. That was fine, he never wanted to escape her anyway. Derek let his hands grip her hips tight, hesitating.

Casey seemed to sense his apprehension, so she whispered, “It’s okay, I’m on the pill.”

He nodded, closing his eyes and pressing his forehead against hers above him. The enormity of the moment caused him to release a nervous sigh. When he opened his eyes to look at her, he was momentarily shocked to see no nervousness from her, she looked sure and determined. Which led him to wonder how long she had thought about this, because Casey never did anything without thinking, making a list, thinking more, and debating with herself over the pros and cons.

She leaned down to kiss him, so softly, that he forgot what they were about to do for a second.

Then, mid-kiss, he felt her reach down, and grab him, holding his cock in place.

“Ready?” she whispered.

“Yeah.”

She sank down onto him as she kissed him again, her wet heat enveloping him in the warmest embrace he had ever felt. His heart skipped to his throat, and he moaned uncontrollably into her mouth. He felt her gasp into his, their lips open in a not-quite kiss, as she moved her hips languidly above him. She kept her slow pace, and Derek couldn’t help but wrap his arms around her tightly, pulling her as close to him as possible. He thrust up into her whenever she sank back down, and the sensation of being inside her, _finally,_ sent tingles through his spine, down to his toes. She let her breasts slide against his chest, sweat building between their bodies, and buried her face into his neck. Her gasps of pleasure hitting his skin and his heart simultaneously gave him motivation to grasp her hips, guiding her movements. Declarations of her name left his lips, whispered against her shoulder between open-mouthed kisses.

Derek distinctly thought to himself, that this, what they were doing, wasn’t just sex, it wasn’t _fucking._

They were making love. An important difference, in his mind. He’s fucked a lot of girls in his life, it was always pure lust and a need for release. Not even when he first slept with Sally, his _first,_ did he feel the overwhelming emotions he felt with Casey. This wasn’t a tryst, it wasn’t a one night stand to him, this was his _forever,_ if she would have him.

“Fuck, _fuck,_ Casey,” he moaned into her ear, his voice desperate with need.

“Derek, you’re so, _mmmh,_ I—” she breathed against his skin, and he loved every whisper of his name from her lips, especially with the sexual undertone in her voice. It would forever be etched into his internal audio file, along with her enunciation of _Der-ek_ she used when he annoyed her.

Their hands moved rapidly over each other, wanting to feel everything all at the same time. Her hips picked up speed, him sliding in and out of her as he thrust to match her pace.

“Casey,” his words started tumbling from his mouth before he could stop them, he needed her to know, he needed to say it to her. She _had_ to know what this meant for him, what _she_ meant to him. “Casey, I can’t— I’m, _nnngh,_ baby, I’m in—I’m in love with you,” he whispered sharply in her ear. His eyes were shut tight, afraid to look at her face for fear of rejection. Casey didn’t stop her movements, in fact, she became more aggressive, hips moving faster and faster at his admission, a loud gasp tearing from her throat.

“I _know,_ Derek, I… _fuuuck,_ I love you, too.”

His breath left him in a _whoosh,_ his heart thudding loudly in his chest, a wave of _pure elation_ came over him. He couldn’t help but let out a light laugh, because, _of course_ she knew. How he had ever thought he could hide something like that from her, he would never know.

“Oh, _god,”_ he ground out, their bodies moved faster together, both racing to reach the same destination. She would forever be the best he ever had, _no one_ could ever compare. She was so honest in her sounds, her movements, it made him love her harder. Derek could no longer live in denial, he told her everything his heart begged to say, in his touches, in his whispers, in the way their bodies connected.

“Derek, I’m, _uuhn,_ I’m gonna—” she panted against his mouth. He could feel her, clenching tightly around his dick, it made the ache low in his gut sing.

“ _Yes,_ please, Case, _please_ baby, I need it. I need you to—”

With a sob, she came around him, her insides pulsating, _squeezing_ him, until he finished with her. Her name left his mouth desperately, breathless.

They lay together, her on top of him, him still inside her, sweaty, and heaving. His arms stayed around her, holding her close to him, breath puffing near her ear. Casey left light kisses on his shoulder and throat, lazy after their bout of love making.

When she lifted her head and their eyes met, her blue boring into his deep brown, he smiled, and her matching grin stabilized him, brought him back down to earth.

“ _Wow,”_ she whispered.

“Yeah,” he huffed, unable to wipe the silly smile from his face. Then, he couldn’t help himself, “Was it better than chocolate ice cream?”

She let out a musical giggle, dropping her forehead to his sternum momentarily, before returning back to him.

“Way better than chocolate ice cream,” she beamed at him.

“Yeah, I get that a lot.”

She playfully smacked his chest. He could get used to this.

_“Hey, Casey.”_

_“Yeah?”_

_“I think you sweated the ointment off. I might need to do it again.”_

_“Well then, get to work, Venturi.”_

**Author's Note:**

> I love Vulnerable!Derek. Thanks for reading, hope it wasn’t too cringe.


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